GRANT TITLE: Innovative neurophysiological techniques for assessing trunk muscle control and function ABSTRACT Impairments in motor control are linked to low back pain and reductions in physical function in the elderly. Unfortunately, many techniques to assess the neural control of movement are not feasible, or directly applicable, to the trunk musculature. Accordingly, we will develop innovative approaches to study these muscles. Specifically, we will work to develop a reliable, fMRI protocol that investigates the activity of the motor neural networks of selected trunk muscles (specific aim 1). We will also develop a reliable muscle functional MRI (mfMRI) protocol to assess the spatial muscle activation patterns of the deeper lumbopelvic muscles (specific aim 2).We will examine the test-retest reliability of these approaches in four distinct target populations: healthy adults, adults with chronic low back pain, older adults, and older adults with high levels of trunk muscle control (i.e., individuals with expertise in Pilates). By enrolling groups of various levels of trunk muscle control, pathology state and age, we will be able to not only determine the intra-individual reliability, but also the inter-individual reliability as we expect the variability of the measures to be influenced by physical ability, pain state and age. Lastly, in an exploratory aim we will examine the association of our novel neurophysiological measures from Aim 1 and 2 with classic biomechanical and muscle function measures (e.g., trunk extensor strength, trunk extensor force-matching steadiness, and static balance). Successfully developing reliable techniques of this nature will result in new and improved research tools for conducting rigorous studies of therapeutic approaches, such as spinal manipulation and yoga, within the context of trunk muscle control and function.